What is the average time taken for RVR readings in a METAR?

A METAR (Meteorological Aerodrome Report) provides vital weather information, including Runway Visual Range (RVR) readings. The average time for RVR readings in a METAR is based on a 10-minute period. This timeframe is established to ensure that the data reflects current visibility conditions reliably, allowing pilots and air traffic controllers to make informed decisions regarding runway use and approach.

The use of a 10-minute average for RVR helps smooth out any short-term fluctuations in visibility caused by transient weather phenomena, ensuring that the reported values represent a more stable and realistic measure of actual conditions. Therefore, relying on a shorter or longer averaging period could lead to inaccurate assessments of visibility, which is critical for safety during takeoffs and landings.